A novel fuzzy adaptive SRUKF algorithm in tightly-coupled INS／GPS systems

Abstract:

In tightly-coupled Inertial Navigation System(INS)／Global Position System(GPS) systems, the filtering precision of Kalman filter (UKF) will be affected seriously by the calculation rounding error leading to the covariance matrix negative definiteness and the time-varying measurement noise in practical application. To deal with this problem, an adaptive square root unscented Kalman filter(NASRUKF) based on fuzzy control theory algorithm is proposed. This algorithm not only can ensure the covariance matrix non-negative definiteness, but also can track and adjust the time-varying measurement noise. Experimental results show that the algorithm has a good adaptability for the time-varying noise with higher accuracy,which makes the system have higher stability and robustness in comparison with UKF algorithm.